Abstract:
SiC at least about 400 micrometers thick, and preferably within the range of about 400-2,000 micrometers thick, is employed to detect electromagnetic radiation having a wavelength less than about 10 micrometers via an acoustic absorption mechanism. The SiC body preferably has a non-dopant impurity level low enough that it does not interfere with a single crystal structure for the SiC, and an approximately uniform thickness with an approximately flat radiation receiving surface.
Abstract:
Method and apparatus are provided for visibly outlining the energy zone to be measured by a radiometer. The method comprises the steps of providing a laser sighting device on the radiometer adapted to emit more than two laser beams against a surface whose temperature is to be measured and positioning said laser beams about the energy zone to outline said energy zone. The apparatus comprises a laser sighting device adapted to emit more than two laser beams against the surface and means to position said laser beams about the energy zone to outline said energy zone. The laser beams may be rotated about the periphery of the energy zone. The laser beams may be rotated about the periphery of the energy zone. In another embodiment, a pair of laser beams are projected on opposite sides of the energy zone. The laser beams may be further pulsed on and off in a synchronized manner so as to cause a series of intermittent lines to outline the energy zone. Such an embodiment improves the efficiency of the laser and results in brighter laser beams being projected. In yet another embodiment, a primary laser beam is passed through or over a beam splitter or a diffraction grating so as to be formed into a plurality of secondary beams which form, where they strike the target, a pattern which defines an energy zone area of the target to be investigated with the radiometer. Two or more embodiments may be used together. A diffraction device such as a grating may be used to form multiple beams. In a further embodiment, additionally laser beams are directed axially so as to illuminate the center or a central are of the energy zone.
Abstract:
The invention relates to a method and an arrangement for measuring the ambient temperature in barely accessible or hazardous locations, in particular in the proximity of textile, paper or similar webs or other work pieces or materials being conveyed, of which at least one property is determined by means of a methodical system, which requires at least the direct ambient temperature as a comparative or reference value. According to the invention, a pyrometric radiation meter known per se is used. A thermal radiator in thermal balance with the environment is positioned directly proximate to the material web. Detection of the heat radiation spectrum and hence an indirect determination of the ambient temperature is carried out by means of the pyrometer via said thermal radiator.
Abstract:
A system for detecting light intensity including a light sensor for sensing light intensity having a capacitance which varies based on light intensity. The light sensor includes first and second layers forming first and second electrodes and a photosensitive dielectric layer disposed between the first and second electrodes. The photosensitive dielectric layer has a dielectric constant that varies with light intensity such that the sensor has a capacitance representative of light intensity. A controller in communication with the sensor measures the capacitance of the sensor, compares the measured capacitance values to stored capacitance values and generates an output signal based on the comparison. The output signal is configured for use in providing an indication of light intensity.
Abstract:
This invention relates to a thermal radiation detection device comprising at least two detectors each comprising an absorbent radiation membrane, held in place by at least two suspension devices (S11, S12, S21, S22) connected to a mechanical anchor point and an electrical anchor point respectively, in which at least one anchor point that is common to two adjacent detectors, is a purely mechanical anchor point for one detector and is at least an electric anchor point for the adjacent detector.
Abstract:
A passive infrared detector has a first sensor (1) for generating an infrared signal, representative of the difference in temperature between a heat source and the background environment of the detector, a second sensor (3), influenced by the ambient temperature in the detector, and an evaluation circuit (2) for processing the infrared signal. The evaluation circuit contains a temperature compensation (4) for influencing the sensitivity of the detector as a function of the ambient temperature. The temperature compensation (4) is designed in such a way that the sensitivity of the detector is not directly influenced by changes in the ambient temperature. Influencing of the sensitivity of the detector takes place with delay and/or as a function of the speed of the change in the ambient temperature.
Abstract:
Method and apparatus are provided for visibly outlining the energy zone to be measured by a radiometer. The method comprises the steps of providing a laser sighting device on the radiometer adapted to emit more than two laser beams against a surface whose temperature is to be measured and positioning said laser beams about the energy zone to outline said energy zone. The apparatus comprises a laser sighting device adapted to emit more than two laser beams against the surface and means to position said laser beams about the energy zone to outline said energy zone. The laser beams may be rotated about the periphery of the energy zone. The laser beams may be rotated about the periphery of the energy zone. In another embodiment, a pair of laser beams are projected on opposite sides of the energy zone. The laser beams may be further pulsed on and off in a synchronized manner so as to cause a series of intermittent lines to outline the energy zone. Such an embodiment improves the efficiency of the laser and results in brighter laser beams being projected. In yet another embodiment, a primary laser beam is passed through or over a beam splitter or a diffraction grating so as to be formed into a plurality of secondary beams which form, where they strike the target, a pattern which defines an energy zone area of the target to be investigated with the radiometer. Two or more embodiments may be used together. A diffraction device such as a grating may be used to form multiple beams. In a further embodiment, additionally laser beams are directed axially so as to illuminate the center or a central are of the energy zone.
Abstract:
A method and apparatus for monitoring the condition of the thermal barrier coating on turbine blades and vanes is provided. The coating is monitored with ultraviolet sensors which can detect ultraviolet radiation emitted from electrical discharges and glow coronas at the surface of the blades and vanes. Such electrical glow discharges and coronas are the result of friction electricity found at the surface of blades and vanes, and are also due to the high pressure, temperature and velocity conditions within the turbine. As the thermal barrier coating deteriorates, the electrical discharges and glow coronas and associated UV emissions decrease in magnitude or have other characteristic changes, thus permitting monitoring of the corona to detect changes in the coating over time.
Abstract:
In a data carrier (1) having an electrical circuit (2), indication means (3) are implemented by means of the electrical circuit (2), which means are arranged so as to determine the occurrence of a change in a parameter influencing the data carrier (1) in relation to at least one threshold value, the at least one threshold value dividing a first parameter range from a second parameter range, and which means are arranged so as to give a permanent indication of the change during the time following the first occurrence of said change.
Abstract:
A microbolometer for the detection of infrared radiation that has a substrate and an array of sensor elements fixed relative to the substrate. In one embodiment, at least some of the sensor elements are less thermally isolated from the substrate than others. The less thermally isolated sensor elements are selected when transients are expected to exist within the sensor array. In another embodiment, all of the sensor elements are deselected when transients are expected.